Dynamics of spall failure in fiber reinforced concrete due to blasting

Dynamic failure in fiber-reinforced concrete (FRC) slabs was studied experimentally and analytically. Due to blasting, damaged areas were created in the specimens, as the crater at the top surface and as the spall at the bottom. It was observed that the averaged diameters and the volumes of the spall failure remarkably decreased with the increase in the flexural toughness of FRC concrete. Because the final damaged areas of the spall could be associated with the resonance modes due to blasting, vibration modes at peak frequencies of blasting were analyzed by applying the boundary element method. From the stress analysis, remarkable agreement between stress-concentrated regions of the resonance modes and the spall areas was confirmed. Thus, dynamics of the spall failure in FRC specimens are clarified.